In North America, Comarum differs from Potentilla by its strikingly deep red to purple petals that are shorter than the sepals and its generally sprawling habit with rooting nodes in distinctly wet habitats. The dark reddish or purplish color generally infuses other floral parts (calyces, anthers, styles). Petals in Potentilla sect. Rubrae (Rydberg) O. Stevens are similarly colored but more or less obcordate and longer than the sepals, and the plants are otherwise typical of that genus in habit, habitat, and palmate leaves.

The fruiting structure of Comarum is intermediate between that of Fragaria and those of most other Potentilleae. As in Fragaria, the torus becomes enlarged and spongy (but not fleshy) in fruit, albeit completely covered by ultimately deciduous achenes. As supported by molecular data (T. Eriksson et al. 1998, 2003), Comarum is more closely related to Fragaria than to Potentilla in the strict sense. It will hybridize with members of Fragaria (J. R. Ellis 1962), giving rise to commercially available pink-flowered strawberries.

This treatment follows J. Soják (2008) in treating Comarum as monospecific; the other species sometimes placed in this genus is Farinopsis salesoviana (Stephan) Chrtek & Soják.